Speed-measuring device



Nov. 17, 1925. 1,561,452

C. R. ALDEN SPEED MEASURING DEVICE Filed Jan. 28, 1925 2 Sheets-Sheet 1 fi -50 Trier 'l I F I N l- 'I-.'N TOR.

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C. R. ALDEN SPEED MEASURING DEVICE 2 Sheets-Sheet 2 Filed Jan 28, 1925 INVENTOR. 6229,9044 E9105 By f fizzy,

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Patented Nov. 17, 1925.

UNITED STATES PATENT-OFFICE.

CARROLL R. ALDEN, F DETROIT, MICHIGAN, ASSIGNOR TO EX-CELL-O TOOL AND MANUFACTURING COMPANY, 013 DETROIT, MICHIGAN.

SPEED-MEASURING nnvron.

Application filed January -To all whom it may concern:

Be it known that I. CARROLL R. ALDEN, a citizen of the United States, and resident of Detroit, in the county of Wayne and State of Michigan. have invented new and useful Improvements in Speed-Measuring Devices, of which the following is a specification.

'This invention relates to means vfor measuring relatively highspeeds of rotation.

The primary object of my invention is the mounting of means upon the rotating mechanism' to be measured for developing electrical current alternations capable of producing musical notes audible in an ordinary head-set ear phone,.'such notes varying according to the "fre uency of such alternations, and then dev loping'a similar note in an adjacent'ear' phone -bymeans of an apparatus under manual control and adjustv able to securevarious notes corresponding ,to those developed by known rotative veloclties.

Ithas long been known that a bipolar ma netized rotor rotating at 15660 R. P. M.

and controlling the ma etic .flux linking with an inductor coil wlll generate in this coil electrical alternations of a frequency of 261 cycles per second. These alternations,-

when impressed on an ordinary head-set ear phone will engender 261 vibrations per second this setting up, the musical note correspondin to middle .0 of the musical reg ister. An other notes havebeen developed by the same device rotating at appropriate speeds. In practice, however it is ex tremely diflicult to'recognize the notes developed at different rotative s eeds and comparison has had to be made with tuning forks or musical instruments, musicallnote engendered by a multipolar alternator driven at a known or measurable 'speed. Very few musical instruments are fitted -for the use, and even when the best are used only highly skilledworkmen can be used for accurately comparingthe respective notes. The apparatus required for making such comparison is not readily portable nor is suitable electric current for "driving certain a paratns above mentioned always availab e. A leading object of my invention is the arrangement of simple, and readily portable means engendering musical measured.

or with the 28, 1925. Serial No. 5,410.

sounds audible in an ear phone adapted to' overlie one ear while an ear phone adapted to overlie the other ear receives sounds develop'edby electrical alternations inaccordance with the speed of the mechanism to be Other. objects parent fromthe following description, whereln reference is made to the accompanying drawings illustrating a preferred i Fig. 1 is a perspectlve view of the mounting on the device to be measured of my improved means for securing electrical alternations.

' Fig. 2 is a front elevation of the manuallyv controlled electrical means for developing sounds to be compared with the sounds de- -veloped by the alternations under the control ofthe device to be measured.

and advantages will be ap- Fig. 3 is a diagrammatic view of the eleotricalapparatus for developing the comparable sounds, and I Fig. 4 is an enlarged detail view of the manually controlled mechanism for controlling the frequency of the alternations by WhlCh, the comparable sounds are secured.

Fig.5 is a cross sectional view on the line 5 -5'of Fig. 4.

Referring now to the "drawings, the numeral -5 designatesthe extremity of the rotating member of a turbine orother device capable of being'rotated at relatively high speeds. It will be understood that turbines driven by steam or. compressed air, engines,

motors and the like may all be measured.

by m improved speed measuring "device, and smce the turbine, etc; forms no essential part of the measuring device, no atscri a complete turbine structure, merely tem t is made herein to illustrate or de- M suflicient being illustrated to depict a preferred manner of mounting the driven pertion of my improved speed measuring de-' tate between the spaced extremities of a the filament.

laminated core 8 of an inductor coil 9, the ends of which coil 'arerespectively connected to the proper terminals 10 of an ordinary ear phone 11, such as is used with the usual telephone head set. By virtue of this arrangement the rotation of the rotor 'disc 7 will eflect alternationsof current in the inductor coil 9 in conformity with the speed of rotation of the rotor disc, and the alternations thus engendered will develo sounds in the ear phone 11 varying accor iing to the frequency of the alternations.

It will, therefore, be apparent that sounds will be devepoped in the ear phone 11 that are comparable with similar sounds de veloped by known rotative speeds and that, accordingly, the speed of rotation of the rotor disc 7 may be determined.

The apparatus fordeveloping the sounds with which. the sounds developed in the ear phone 11 are compared will now be described: An oscillatory circuit including the usual three-electrode vacuumtube 12 is arranged to actuate the ear phone 13 so that the sounds engendered in the ear phone 13 varies in accordance with the frequency of the oscillatory circuit. in 'Fig. 3 the filament 14 of the vacuum tube is connected with the terminals of an A-battery 15, a suitable filament rheostat 16 being interposed between the battery and The plate 17 "of the tube is connected to the positive terminal of a"B- battery 18, the negative terminal of which is connected with one extremity of a condenser and variable inductance 19, preferbly constructed with a coil surrounding a tapered core19 adjustable relatively to the coil to vary the frequency of the oscillatory circuit by varying inductance of the circuit, while the opposite extremity-of the condenser 50 and inductance coil-19 are connected by a wire 20 with the filament 1,4

of the vacuum 'tube.= Coil 19 is superimarranged in the circuit with one of its terminals connected to one extremity of the coil 19 and its other terminal connected with the other extremity of coil 19". By

As best illustrated.

menus virtue of this arran ement the oscillatory circuit will pro uce sounds in the ear phone 13 in accordance with the variations of the frequency of the oscillatory circuit, such variations being secured by manually adjusting the position of the tapered core 19 of the inductance coil 19. As herein shown, I have connected the. tapered core 19 with a rack 22 meshing with a pinion fixed on the shaft 23 of a dial 24 so that the rotation of the dial in the proper direction will longitudinally 7 move the tapered core 19 relatively to the coil 19 to increase or diminish the induc tance of the coil 19 and thereby vary the frequency of the oscillatory circuit. I preferably mark upon the face of the dial 24 the number of revolutions per minute needed to produce the note engendered in the ear phone 13 by ,the oscillatory circuit at varying positions of the tapered core 19.

This must be determined empirically. Reference to various authoritative tables, h0W-.'

ever, will show that a note correspondingto the middle G of the'musical register is developed when the alternations of a bipolar alternating current generator 'driven at so on, or If desired the half notes can'.be also marked. By marking the number of. revolutions per minute required to devel note in place of the note itself, it ma es it much easier. for the operator to quickl determine the rotative speed of the evice being measured. It will be ap arent' that graduations 'can be made on t e dial between the various points marked during the ex erimental setting above descrl and at, 'accor'dingly, sounds intermediate the notes of the musical register can be compared with sounds developed under the gontrol' of the device to-be measured, wherey quic y determined through the agency of my improved device.

While it will be apparent that the illus trated embodiment of my invention herein disclosed is well calculated to adequately.

fulfill the objects and advantages primarily stated, it is to be understood that the invent on is susceptible to variation, modifi-. spirit and cation and chan within the scope ofthe subjomed claims.

the

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ractically any rotative speed can be.

Having described my invention, I claim:

1. In a speed measuring device, means under the control of the mechanism to be measured for electrically producing a musical note, and manually controlled means for electrically producing a corresponding note adjacent the first mentioned note for comparison' therewith.

2. In a speed measuring device, means under the control of the mechanism to be measured for electrically producing a musical note, and an oscillatory circuit for electrically producing a corresponding note adjacent the first mentioned note for comparison therewith, including manually operative means for varying the frequency of the circuit. a

3. In a speed measuring device, means under the control of the mechanism to be measured for electrically producing a musical note including an ear phone, manually controlled means for electricall producing a corresponding note adjacent t e first mentioned note for comparison therewith, and

an ear phone connected with the last mentioned means to localize the audibility of the note produced thereby.

4. In a speed measuring device, means under the control of the mechanism to be measured for electrically producing a musical note, an" oscillatory circuit for electrically producing a corresponding note adjacent the first mentioned note for comparison therewith, including manually operative means for varying the frequency of the circuit, and a three-electrode vacuum tube having its plate and grid connected to the manually operative means.

' 5. In a speed measuring device, a pair of head-set ear-phones, and separate electric mechanisms for producing in each ear phone substantially the same musical note, one of the said mechanisms'being under the control of the device whose speed is being measured, and the other being under manual control.

6. In a speed measuring device, a. pair trol of the device whose speed is being whose measured, the other including an oscillatory circuit having manually operative means for varying the fre uency of the circuit, and a three-electro e vacuum tube id and plate are connected to such manual y operative means.

8. In a speed measuring device, a magnetized rotor disc secured to the mechanism whose speed is being measured, an inductor coil having the ends of its core adjacent the rotor disc, an ear phone connected with the inductor coil, an oscillatory circuit having manually operative means for varying the frequency of the circuit, and an ear phone connected to the oscillatory circuit.

9. In a speed measuring device, a niagnetized rotor disc secured to the mechanism whose speed is being measured, an'inductor coil having the ends of its core ad: jacent the rotor disc, an ear hone connected with the inductor coil, W ereby musical notes will be audible in the ear phone according to the frequency of rotations of the rotor disc, an oscillatory circuit for producing musical notes comparable with the first mentioned musical notes, including a three-electrode vacuum tube, and manually operative means for varying the frequency 0 the oscillatory circuit.

10. In a spec measuring device, a magnetized rotor disc secured to the mechanism whose s eed is being measured, an inductor coil having the ends of its core adjacent the rotor disc, an ear phone connected with the inductor coil, whereb musical notes will be audible in the ear p one according to the frequency of rotations of the rotor disc, an oscillatory circuit for producing musical notes comparable with the first mentioned musical notes, including a three-electrode vacuum tube, an A-battery connected to the filament of such tube, a B-battery connected between the plate and filament of the tube, a variable inductance also connected between the plate and filament of the tube and having manually operative means for varying the frequency of the circuit, and anjear phone connected with the circuit to render audible the musical notes produced thereby.

11. In a speed measuring device, a mag netized rotor disc secured to themechanism whose speed is being measured, an inductor coil havlng the ends of its core adjacent the rotor disc, an ear phone connected with the inductor coil, whereby musical notes will .be audible in the ear phone according to the frequency of rotations of the rotor disc, an oscillatory circuit for producing musical notes comparable with the first mentioned musical notes, including a three-electrode vacuum tube, 'and manually operative means for varying the frequency of the oscillatory circuit comprisin a pair of superposed coils, a core mova 1e wlthin said coils, and means for moving the core.

. 12. In a speed measuring device, a magnetized rotor disc secured to the mechanism whose speed is being measured," an inductor coil having the ends of its core adjacent the rotor disc, an ear phone connected with. the

inductor coil, whereby musical notes will be audible in/the ear phone according to the frequency of rotations of the rotor disc,an

oscillatory circuit for reducing musical notes comparable with t e first mentioned musical notes, including a three-electrode vacuum tube, manually operative means for varying the frequency of the oscillatory circuit comprising a variable inductance arranged between the plate and filament of said coils and carryin carrying a pinion mes ing with the rack.

In witness whereof I hand.

reunto set my CARROLL R. ALDEN.

a rack, and a dial 10 

